This invention relates to the field of anti-graffiti paints, more particularly to polyurethane coatings with resistance to graffiti paint and to methods of imparting graffiti resistance to polyurethane coatings.
Graffiti paint contains dye and solvents, the dye molecules tending to diffuse or penetrate into the coating after the graffiti paint is applied onto a coating surface. The deeper the penetration, the more difficult is the removal process. One approach in the current art is to use perfluoro-, fluorine-, or silicone-modified materials, including polyols, to reduce the surface energy of the coating and thereby dewet any graffiti paint and reduce contact. The less the contact of graffiti paint on the surface, the less amount of undesired graffiti paint will stay on the coating. Also most of the modifications are focused on the polyol side in prior two component waterborne polyurethane systems.